Edible oil refining method

Edible oil refining operation method:

(1) Before sending rapeseed oil into the crude oil pump into the refining tank, check whether the pipeline valve is normal. After the oil is sent to each tank, immediately close the oil inlet valve. For the crude rapeseed oil refined in the oil tank, the foam on the oil surface must be removed to make the oil surface smooth, and the oil is allowed to stand for an appropriate period of time so that there is no foam in the oil. Adjust the crude oil temperature to 25-35°C.

(2) Preparation of lye. Weigh out the required amount of lye (purity must be identified first), mix it with an appropriate amount of water, start the alkali pump, and circulate the lye to completely melt it. Reduce the temperature of the lye to 25-30°C, measure the temperature of the lye wave with a Baume meter, and adjust it to 10-12°.

(3) When the oil surface of the crude oil is smoothed and the temperature is stable at 25-35℃, start the stirrer to start stirring, firstly turn slowly (20r/min) and stir for 1min, then change to fast speed (40r/min), stirring at the same time , Open the alkali tank valve and put in the alkali solution. The addition time of lye is generally about 15 minutes. After the lye is released, continue to stir quickly until the oil and soap particles are clearly separated. The stirring time is about 3-3.5h. When the oil and soap feet are clearly separated, stir slowly and open the heating steam door (vapor pressure 1.4kgf) /C㎡), when the oil temperature rises to 60°C, immediately stop stirring (oil temperature should be kept at 1°C/min, the maximum temperature should not exceed 65°C), and close the steam valve to cool down by itself * precipitation (precipitation time About 8 hours). After checking that the oil delivery valve pipeline is normal, pump the oil into the washing tank. When pumping to the interface between the oil and the deposited soap feet, be careful not to pump out the soap feet, and at the same time, pump out the oil.

(4) Water washing heats the oil pumped into the washing tank and at the same time starts the stirrer to add 75-80℃ hot water to keep the oil temperature at 80-85℃ (the temperature must not exceed 85℃). When the water has been added (the amount of water added is 15%-20% of the oil, the time of adding water is 38-40min), stop heating and continue stirring for 15 minutes, that is, stop stirring, settling for 2h (the yith time), and wash the bottom of the tank with water Open the drain valve and let go of about 3/4 of the washing water (first put the oil in the pipeline into the oil-water separation tank before letting go of the washing water). Next, close the drain valve, open the valve leading to the oil-water separation tank, and slowly add the remaining oil-water mixture. In the first water washing, all the viscous material in the middle layer of oil and water must be put into the separation tank until good oil is seen, and then the valve is closed. The oil-water separation should be handled by a dedicated person. When performing separation in the separation tank, the heating tube in the tank should be opened to increase the temperature (not exceeding 80°C). After separation, the water should be released and the remaining oil should be recovered. Follow the above method to continue washing the oil machine with water until the washing water is completely clear. The sedimentation time of the first washing is 1.5h.

(5) Check whether the relevant pipeline valves are normal before dehydration and transportation, and then pump the water-washed oil into the vacuum dehydration tank. At the same time, open the steam valve, start the vacuum pump and agitator, adjust the cold * water of the condenser, start the circulating oil pump, and accelerate the vacuum dehydration tank. Oil circulation. The vacuum degree of the vacuum dehydration tank is kept above 0.0867MPa. The dehydration time is about 3h, counting from the oil delivery in the dehydration tank, the dehydrated oil should be sampled and inspected by the quality inspector. When it is found that the dehydration is insufficient, the dehydration must be continued. The dehydration temperature is maintained at about 70°C. After dehydration is complete, stop the vacuum pump, open the air valve, and slowly add air. Check whether the pipeline valve is normal, and then the conveyed oil is cooled to 25–30℃ through the cold pipe and flows into the sedimentation tank for pressure filtration.

(6) Filter press check whether the filter press pipeline valve is normal. Check that the oil temperature must be below 30°C. After the oil is filtered, stop the oil filter pump to close the valve, gently open the filter plate to allow the internal oil to flow into the oil pan, and then remove the filter residue on the filter cloth. Check the usage of the filter cloth and prepare to be replaced or washed. The residual oil of the filter cloth should be separated and recovered by a centrifuge.

Effects that can be achieved by edible oil after refining process:

The grease processed by the refining machine has a transparent color, no precipitation after long-term storage, no frothing, no oily smoke, and reaches the national* edible oil standard. It can be directly filled and sold. It is suitable for processing and small-scale oil processing plants. .